Hello! I have a non X code 69 camaro with a build date of 10B. 57 57 paint with 721 interior. It has the hole in the firewall for the muncie speedometer cable. Factory discs on the front. The fenders appear to be original to the car. The Z28 emblems appear to be original to the car. Can see some green under the black repaint job done around 1989. On the side of the floor pan hump it reads 1969 CHEV, 1ST DRK GREEN REAR B/SS/37 9/23/68. Can anyone tell me what any of this means?

I have that same "LG7" yellow crayon marks on my rear bulkhead. "LG" is "Light Green" interior color. "7" is for the x-77 trim. The car I have was a light green color custom trim level car built 10A of '68

"My" interpretation of this mark - The Fisher body line needed a clue of what color to spray the interior areas that are visible once the car is finished. The light green interior color will show through the air vents and probably other places so they had to paint that before the interior trim was installed. THe CRG has not weighed in on this but that is my best guess. You and I are close in build week so it makes sense to me that they were marking them that way at that time.

The black magic marker lettering is a new one to me. I doubt it was factory markings but who knows.

Thanks for the info. Everything else seems to point to a z28 too. Big thanks to Jerry@CHP for suggesting I look around the cowl for traces of the original striping. Found them under the repaint done around 1989.